The threonine deaminase formed under anaerobic conditions by Salmonella typhimurium is induced by l-serine and l-threonine, is catabolite repressible, requires cyclic adenosine 3',5'-monophosphate for its synthesis and adenylic acid for optimal activity, and is immunologically different from biosynthetic threonine deaminase.

A rapid method for purifying L-threonine dehydrogenase from Escherichia coli K-12 cells, grown on a medium containing L_-threonine as carbon source, has been developed. The procedure consists of three fractionation steps of which the last is adsorption and elution of the enzyme from a column of Blue dextran-Sepharose. Homogeneous and stable samples of the dehydrogenase are obtained. L-Threonine...

Two auxotrophic mutants of Escherichia coli have been shown to accumulate significant amounts of l-threonine in the culture medium. One mutant, 13071, is deficient in alpha,epsilon-diaminopimelic acid (DAP), and the other, 13070, is deficient in both DAP and methionine. Accumulation of l-threonine by 13071 in a synthetic medium with mannitol as the carbon source at 37 C incubation temperature w...

The work reported herein describes the results of endeavors to isolate and characterize the enzymes involved in the dehydrative deamination of the /?-hydroxyamino acids, serine and threonine. Preparations have been obtained which act on threonine and serine separately. L-Threonine dehydrase and L-serine dehydrase were separated by controlled heat denaturation and subsequent ammonium sulfate fra...

In addition to being an essential amino acid in protein synthesis, threonine is an integral component of gut function. To verify the effects of l-threonine on gut function, Babcock Brown layers (n = 960; 40 wk of age) were allocated to 5 dietary treatment groups, each of which included 6 replicates of 32 hens. Each group received the same basal diet formulated with corn, peanut meal, and crysta...

Preclinical data indicate that the administration of the amino acid L-threonine increases glycine levels in rat spinal cord. In order to investigate glycinergic mechanisms in spasticity, and other signs of the upper motor syndrome, we gave 4.5 and 6.0 g/day of L-threonine to 18 patients with familial spastic paraparesis (FSP) according to a double-blind, crossover protocol. The response to trea...